//
// Created by 123 on 2025/1/10.
//
#include "iostream"
#include "functional"

void testNegate(){
    std::negate<int> n;
    std::cout << n(50) << std::endl;
}

void testPlus(){
    std::plus<int> p;
    std::cout << p(10,20) << std::endl;
}

void testMinus(){
    std::minus<int> m;
    std::cout << m(20,20) << std::endl;
}

int main147(){
    testNegate();
    testPlus();
    testMinus();
}